Combined head up display (HUD) and camera system

ABSTRACT

An optical arrangement for a motor vehicle includes a head up display light field emitter that emits a light field. At least one mirror is positioned to reflect the light field such that the light field is again reflected by a windshield of the vehicle, and such that the light field is visible to a driver of the vehicle as a virtual image. The at least one mirror has a transparent section. A driver monitoring camera is positioned to capture an image of a face of the driver through the transparent section of the at least one mirror.

CROSS-REFERENCED TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 15/668,903 filed on Aug. 4, 2017, which claims benefit of U.S.Provisional Application No. 62/370,991 filed on Aug. 4, 2016, thedisclosures of which are hereby incorporated by reference in theirentireties for all purposes.

FIELD OF THE INVENTION

The disclosure relates to combining a head up display (HUD) and a drivermonitoring camera in a motor vehicle.

BACKGROUND OF THE INVENTION

A head up display emits light that reflects from the front windshield tobe seen by the driver. The light appears to come from a virtual image infront of the driver and in front of the windshield.

Conventional head up displays create the virtual image by first using adisplay to create an image. Next, the light from the image is reflectedfrom one or more mirrors, and then the light from the mirrors isreflected from the windshield. The mirrors are designed and positionedrelative to the display so that the light seen by the driver, which isreflected from the windshield, appears to come from a virtual image thatis outside of the vehicle. The mirrors and display are typicallycontained in a package that occupies a volume beneath the top surface ofthe dashboard.

Driver monitoring cameras are currently difficult to place in thevehicle. The driver monitoring cameras need to have a clear,unobstructed front angle view of the driver, but the cameras cannot beallowed to obstruct the driver's view of the road. Today's systems arelocated on the steering column or are mounted on top of the dash. Bothlocations are non-optimal since their view can be obstructed, and thecamera itself can be distracting to the driver.

SUMMARY

The present invention may provide an arrangement in which a drivermonitoring camera is combined in the same module housing with the HUDlight field emitter. The camera and HUD light field emitter may sharethe same optics, such as a same mirror. Combining the camera with theHUD enables the same optics that deliver the visual HUD display to thedriver to also be used to deliver the image of the driver's face to thecamera. The driver monitoring camera may be combined with any part ofthe HUD optics. For example, any of the reflecting mirrors may include asmall hole through which the camera can see the image of the driver'sface. The camera may also be placed alongside the HUD package itself andreceive the image of the driver's face after the image has beenreflected off of the windshield alone or windshield plus any number ofmirrors or lenses. Additionally, the image may be reflected off coatedlenses that reflect IR light but transmit visible light.

In one embodiment, the invention comprises an optical arrangement for amotor vehicle, including a head up display light field emitter thatemits a light field. At least one mirror is positioned to reflect thelight field such that the light field is again reflected by a windshieldof the vehicle, and such that the light field is visible to a driver ofthe vehicle as a virtual image. A driver monitoring camera is positionedto capture an image of a face of the driver that is reflected off of thewindshield directly or including one or more mirrors. Alternatively, itis possible for the driver monitoring camera to catch the reflectiondirectly off the windshield without the use of any mirrors.

In another embodiment, the invention comprises an optical method for amotor vehicle, including emitting a light field based on image data. Thelight field is reflected with at least one mirror such that the lightfield further reflects off of a windshield of the motor vehicle and isvisible to a driver of the vehicle as a virtual image. A drivermonitoring camera is used to capture an image of a face of the driverthat is reflected off of the windshield and the one or more mirrors.

In yet another embodiment, the invention comprises an opticalarrangement for a motor vehicle, including a head up display light fieldemitter that emits a light field. At least one mirror is positioned toreflect the light field such that the light field is again reflected bya windshield of the vehicle, and such that the light field is visible toa driver of the vehicle as a virtual image. At least one mirror has atransparent section for IR light. A driver monitoring camera ispositioned to capture an image of a face of the driver through thetransparent section of the at least one mirror.

In still another embodiment, the invention comprises an opticalarrangement for a motor vehicle, including a head up display light fieldemitter that emits a light field. At least one optical element ispositioned to reflect the light field such that the light field is againreflected by a windshield of the vehicle, and such that the light fieldis visible to a driver of the vehicle as a virtual image. The at leastone optical element includes at least one mirror and/or at least onelens. The at least one optical element is reflective to visible lightand transparent for IR light. A driver monitoring camera is positionedto capture an IR image of a face of the driver reflected off of thewindshield and passing through the at least one optical element.

An advantage of the present invention is that it solves the problem ofwhere to place a driver monitoring camera by combining it with the HeadsUp Display (HUD).

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present invention will be had uponreference to the following description in conjunction with theaccompanying drawings.

FIG. 1 is a schematic view of one example embodiment of a combined HUDand driver monitoring camera arrangement of the present invention.

FIG. 2 is a flow chart of one embodiment of an optical method of thepresent invention for a motor vehicle.

FIG. 3 is a schematic view of another example embodiment of a combinedHUD and driver monitoring camera arrangement of the present invention.

FIG. 4 is a schematic view of yet another example embodiment of acombined HUD and driver monitoring camera arrangement of the presentinvention.

FIG. 5 is a schematic view of still another example embodiment of acombined HUD and driver monitoring camera arrangement of the presentinvention.

FIG. 6 is a schematic view of a further example embodiment of a combinedHUD and driver monitoring camera arrangement of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates one example embodiment of a combined HUD and drivermonitoring camera arrangement 10 of the present invention, including aHUD display screen and driver monitoring camera module 12, a fold mirror14, an aspheric mirror 16, and a windshield 18. Module 12 includes a HUDdisplay screen 20 and a driver monitoring camera 22. HUD display screen20 and driver monitoring camera 22 may be disposed within a commonhousing, or may be disposed adjacent to each other. HUD display screen20 and driver monitoring camera 22 may be illustrated as beingphysically separated by a substantial distance in FIG. 1 for ease ofillustration, but may be close enough together to share optics includingmirrors 14, 16 and windshield 18. That is, a light field from screen 20may be reflected by mirrors 14, 16 and windshield 18 and be seen by adriver 24. Similarly, an image of a face of driver 24 may be reflectedby windshield 18, mirrors 16, 14 and be captured by camera 22.

During use, HUD display screen 20 emits a light field that is reflectedsequentially off of mirror 14, mirror 16, and windshield 18 such thatthe light field is visible to driver 24 as a virtual image 26 thatappears to be disposed over the front bumper of the vehicle. Camera 22captures an image of the face of driver 24 that is reflectedsequentially off of windshield 18, mirror 16, and mirror 14.

In another embodiment, instead of capturing the image of the driver'sface as a reflection off of windshield 18, mirror 16, and mirror 14,camera 22 captures the image of the driver's face directly alongimaginary line 28 and through a throughhole 30 in mirror 14. Instead ofthroughhole 30, mirror 14 may have a transparent section through whichcamera 22 may see the driver's face. Imaginary line 28 may extendthrough an air gap in steering wheel 32, or may be disposed outside ofsteering wheel 32. It is also possible for imaginary line 28 to beoffset from mirror 14 such that no throughhole or transparent section inmirror 14 is needed.

FIG. 2 is a flow chart of one embodiment of an optical method 200 of thepresent invention for a motor vehicle. In a first step 202, a lightfield is emitted based on image data. For example, HUD display screen 20may emit a light field based on image data from an electronic processor(not shown).

In a next step 204, the light field is reflected with at least onemirror such that the light field further reflects off of a windshield ofthe motor vehicle and is visible to a driver of the vehicle as a virtualimage. For example, the light field emitted by HUD display screen 20 maybe reflected by mirrors 14, 16 such that the light field furtherreflects off of windshield 18 of the motor vehicle and is visible todriver 24 of the vehicle as a virtual image 26.

In a final step 206, a driver monitoring camera is used to capture animage of a face of the driver that is reflected off of the windshieldand the at least one mirror. For example, driver monitoring camera 22may be used to capture an image of a face of driver 24 that is reflectedoff of windshield 18 and mirrors 14, 16.

FIGS. 3-7 illustrate embodiments of an inventive combined HUD and drivermonitoring camera arrangement including use of a coating that is eitherreflective for infrared (IR) light and transparent for visible light, orvice versa (e.g., transparent for IR and reflective for visible). Thismakes it possible for a windshield or optical element to function as alens in one spectrum while functioning as a mirror in the otherspectrum. The windshield or optical element functioning as both a lensand a mirror enables the camera to get a clear image of the face whilenot interfering with the HUD image presented to the driver.

Arrangement 300 includes a windshield 318 and a camera 322, and may notinclude a HUD. Windshield 318 includes a coating that is reflective ofIR energy and at least partially transparent to visible light. Thus,driver 324 may see the road through windshield 318, as indicated at 334,and windshield 318 may reflect IR light to camera 322, as indicated at336, such that camera 322 may capture images of driver 324.

Arrangement 400 includes a windshield 418, a camera 422, and a combiner(lens) 438, and may not include a HUD. Combiner 438 includes a coatingthat is reflective of IR energy and at least partially transparent tovisible light. Thus, driver 424 may see the road through windshield 418and combiner 438, as indicated at 434, and combiner 438 may reflect IRlight to camera 422, as indicated at 436, such that camera 422 maycapture images of driver 424.

Arrangement 500 includes a windshield 518, a camera 522, at least oneoptical element 538 which may include at least one lens and/or at leastone mirror, and a HUD display screen 520. Windshield 518 includes acoating that is reflective of IR energy and at least partiallytransparent to visible light. Optical element 538 is reflective of IRenergy and transparent to visible light, perhaps by virtue of includinga coating with these properties. Thus, driver 524 may see the roadthrough windshield 518, as indicated at 534, and optical element 538 mayreflect IR light to camera 522, as indicated at 536, such that camera522 may capture images of driver 524. Further, optical element 538 doesnot interfere with a light field that is emitted by HUD display screen520 and reflected off windshield 518 to driver 524.

Arrangement 600 includes a windshield 618, a camera 622, at least oneoptical element 638 which may include at least one lens and/or at leastone mirror, and a HUD display screen 620. Windshield 618 includes acoating that is reflective of IR energy and at least partiallytransparent to visible light. Optical element 638 is transparent to IRenergy and reflective of visible light, perhaps by virtue of including acoating with these properties. Thus, driver 624 may see the road throughwindshield 618, as indicated at 634, and optical element 638 may pass IRlight to camera 622, as indicated at 636, such that camera 622 maycapture images of driver 624. Further, optical element 638 reflects alight field that is emitted by HUD display screen 620 such that thelight field is reflected off windshield 618 to driver 624. The foregoingdescription may refer to “motor vehicle”, “automobile”, “automotive”, orsimilar expressions. It is to be understood that these terms are notintended to limit the invention to any particular type of transportationvehicle. Rather, the invention may be applied to any type oftransportation vehicle whether traveling by air, water, or ground, suchas airplanes, boats, etc.

The foregoing detailed description is given primarily for clearness ofunderstanding and no unnecessary limitations are to be understoodtherefrom for modifications can be made by those skilled in the art uponreading this disclosure and may be made without departing from thespirit of the invention.

What is claimed is:
 1. An optical arrangement for a motor vehicle, thearrangement comprising: a head up display light field emitter configuredto emit a light field; at least one mirror positioned to reflect thelight field such that the light field is again reflected by a windshieldof the vehicle, and such that the light field is visible to a driver ofthe vehicle as a virtual image, the at least one mirror having atransparent section; and a driver monitoring camera positioned tocapture an image of a face of the driver through the transparent sectionof the at least one mirror, wherein the transparent section of the atleast one mirror comprises a throughhole.
 2. The optical arrangement ofclaim 1 wherein the transparent section of the at least one mirror isformed of a transparent material.
 3. The optical arrangement of claim 1further comprising an electronic processor configured to: receive imagedata from the camera; and cause a stimulus to be presented to the driverdependent upon the image data.
 4. The optical arrangement of claim 3wherein the stimulus is presented to the driver within the virtual imageproduced by the head up display light field emitter.
 5. The opticalarrangement of claim 1 further comprising an electronic processorconfigured to: receive image data from the camera; and change anoperational parameter of the vehicle dependent upon the image data. 6.The optical arrangement of claim 1 wherein the head up display lightfield emitter and the driver monitoring camera are disposed within acommon housing.
 7. The optical arrangement of claim 1 wherein the headup display light field emitter and the driver monitoring camera areadjacent to each other.
 8. The optical arrangement of claim 1 whereinthe at least one mirror comprises a fold mirror and an aspheric mirror.9. The optical arrangement of claim 8 wherein the transparent section isin the fold mirror.
 10. An optical arrangement for a motor vehicle, thearrangement comprising: a head up display light field emitter configuredto emit a light field; at least one mirror positioned to reflect thelight field such that the light field is again reflected by a windshieldof the vehicle, and such that the light field is visible to a driver ofthe vehicle as a virtual image, the at least one mirror including a foldmirror having a transparent section; and a driver monitoring camerapositioned to capture an image of a face of the driver through thetransparent section of the fold mirror, wherein the transparent sectionof the fold minor comprises a throughhole.
 11. The optical arrangementof claim 10 wherein the transparent section of the fold mirror is formedof a transparent material.
 12. The optical arrangement of claim 10further comprising an electronic processor configured to: receive imagedata from the camera; and cause a stimulus to be presented to the driverdependent upon the image data, wherein the stimulus is presented to thedriver within the virtual image produced by the head up display lightfield emitter.
 13. The optical arrangement of claim 10, furthercomprising a steering wheel having an air gap, the driver monitoringcamera being positioned to capture an image of a face of the driverthrough the air gap.